[PATCH] drm/amdgpu: Add a new module param to disable d3cold

[Ma, Jun]

Hi Lijo,

On 11/30/2023 5:18 PM, Lazar, Lijo wrote:
> 
> 
> On 11/30/2023 11:59 AM, Ma, Jun wrote:
>> Hi Alex,
>>
>> On 11/30/2023 12:39 AM, Alex Deucher wrote:
>>> On Wed, Nov 29, 2023 at 11:37 AM Ma Jun <Jun.Ma2 at amd.com> wrote:
>>>>
>>>> Some platforms can't resume from d3cold state, So add a
>>>> new module parameter to disable d3cold state for debugging
>>>> purpose or workaround.
>>>
>>> Doesn't the runpm parameter already handle this?  If you set runpm=0,
>>> that should disable d3cold.
>>>
>> runpm=0  prevents calls to driver runtime_suspend/resume functions.
>> While d3cold=0 allows calls to runtime_suspend/resume functions and puts
>> the device in d3hot state instead of d3cold.
>>
> 
> Why not use the sysfs node to change "d3cold_allowed" on the device's 
> upstream bridge?
> 
It seems the same question as Mario. Please refer to my reply to his question.

Regards,
Ma Jun

> Thanks,
> Lijo
> 
>> Regards,
>> Ma Jun
>>
>>> Alex
>>>
>>>>
>>>> Signed-off-by: Ma Jun <Jun.Ma2 at amd.com>
>>>> ---
>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 1 +
>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 +++++++
>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    | 8 ++++++++
>>>>   3 files changed, 16 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> index a9f54df9d33e..db9f60790267 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>> @@ -166,6 +166,7 @@ extern char amdgpu_lockup_timeout[AMDGPU_MAX_TIMEOUT_PARAM_LENGTH];
>>>>   extern int amdgpu_dpm;
>>>>   extern int amdgpu_fw_load_type;
>>>>   extern int amdgpu_aspm;
>>>> +extern int amdgpu_d3cold;
>>>>   extern int amdgpu_runtime_pm;
>>>>   extern uint amdgpu_ip_block_mask;
>>>>   extern int amdgpu_bapm;
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> index 22b6a910b7f2..90501c44e7d0 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> @@ -264,6 +264,13 @@ bool amdgpu_device_supports_px(struct drm_device *dev)
>>>>   bool amdgpu_device_supports_boco(struct drm_device *dev)
>>>>   {
>>>>          struct amdgpu_device *adev = drm_to_adev(dev);
>>>> +       struct pci_dev *parent;
>>>> +
>>>> +       if (!amdgpu_d3cold) {
>>>> +               parent = pcie_find_root_port(adev->pdev);
>>>> +               pci_d3cold_disable(parent);
>>>> +               return false;
>>>> +       }
>>>>
>>>>          if (adev->has_pr3 ||
>>>>              ((adev->flags & AMD_IS_PX) && amdgpu_is_atpx_hybrid()))
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> index 5f14f04cb553..c9fbb8bd4169 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> @@ -145,6 +145,7 @@ char amdgpu_lockup_timeout[AMDGPU_MAX_TIMEOUT_PARAM_LENGTH];
>>>>   int amdgpu_dpm = -1;
>>>>   int amdgpu_fw_load_type = -1;
>>>>   int amdgpu_aspm = -1;
>>>> +int amdgpu_d3cold = -1;
>>>>   int amdgpu_runtime_pm = -1;
>>>>   uint amdgpu_ip_block_mask = 0xffffffff;
>>>>   int amdgpu_bapm = -1;
>>>> @@ -359,6 +360,13 @@ module_param_named(fw_load_type, amdgpu_fw_load_type, int, 0444);
>>>>   MODULE_PARM_DESC(aspm, "ASPM support (1 = enable, 0 = disable, -1 = auto)");
>>>>   module_param_named(aspm, amdgpu_aspm, int, 0444);
>>>>
>>>> +/**
>>>> + * DOC: d3cold (int)
>>>> + * To disable d3cold (1 = enable, 0 = disable). The default is -1 (auto, enabled).
>>>> + */
>>>> +MODULE_PARM_DESC(d3cold, "d3cold support (1 = enable, 0 = disable, -1 = auto)");
>>>> +module_param_named(d3cold, amdgpu_d3cold, int, 0444);
>>>> +
>>>>   /**
>>>>    * DOC: runpm (int)
>>>>    * Override for runtime power management control for dGPUs. The amdgpu driver can dynamically power down
>>>> --
>>>> 2.34.1
>>>>
> 
>